Bug 612090 – sys-apps/portage: add support for PROPERTIES="sparse-files" in ebuilds

• Status: CONFIRMED
• Product: Portage Development

[Description Zac Medico 2017-03-09 03:53:15 UTC]

It would be nice if ebuilds could set RESTRICT="sparse-files" to assert that sparse files are supported.

[Comment 1 Brian Dolbec (RETIRED) 2017-03-09 19:24:56 UTC]

Isn't that backwards???

RESTRICT="sparse-files"  means to me that they are NOT supported.

[Comment 2 Zac Medico 2017-03-09 19:29:39 UTC]

I suppose we could make it PROPERTIES="sparse-files" instead. Patrick, sounds good to you?

[Comment 3 Patrick McLean 2017-03-09 19:33:27 UTC]

I am fine with that, the main thing I want is the ability to have the package manager bomb out rather than happily merge a ~100G sparse file as something that is not sparse.

[Comment 4 Zac Medico 2017-12-09 22:25:56 UTC]

The tar --sparse option is not currently used to pack binary packages.

Current versions of quickpkg do not support creation of sparse entries, and python's tarfile documentation states that sparse file support is read-only:

https://docs.python.org/3/library/tarfile.html#supported-tar-formats

Maybe there's some way to make the tarfile API write sparse entries that have been manually created somehow. The tar manual has an informative "Storing Sparse Files" section:

https://www.gnu.org/software/tar/manual/html_section/tar_92.html